Tracer ammunition, that is, ammunition including pyrotechnic compositions, has long been employed by the military and other organizations to provide a visible "trace" of a projectile's trajectory after the projectile has been fired from a weapon. Such tracer ammunition provides visual assurance that all rounds or slugs are being delivered to the exact area wherein it is desired to direct the fire. Accordingly, for small arms, it is important that the tracer rounds be similar in size, weight and configuration to the other non-tracer rounds so that all ammunition will exhibit similar trajectories and flight patterns For cannon caliber rounds, all types of ammunition (e.g., armor-piercing, high-explosive, target-practice, etc.) will contain a tracer.
Such prior-art pyrotechnic compositions have conventionally been loaded into a hole drilled in the base of the projectile to a predetermined depth wherein the depth of the hole is related to the total visible burning time required. The visible burning time for a pyrotechnic tracer projectile is usually defined as the time over which the gunner or other observer can actually see the "trace" of the projectile. This hole in the base of the projectile is filled during the manufacturing process with a pyrotechnic powdered composition, which composition must be consolidated under extremely high compression forces, usually by employing a hydraulic or pneumatic press. This consolidation process may require several consolidation steps and may require the addition of a separate igniter composition in order to assure ignition after firing. The extremely high tamping pressures previously required in the tracer ammunition manufacturing process proved to be extremely cumbersome and difficult when encountering small cavity projectiles to thereby greatly increase production costs while at the same time decreasing reliability and predictability.
The consolidation process presently necessary to produce the currently available tracer ammunition has rendered the manufacture of such ammunition unadaptable to fast production by employment of the usual automatic ammunition manufacturing equipment. This results in the requirement to utilize special, slow functioning machines, thus considerably slowing down the production of tracer ammunition and causing increased production costs. The consolidation process also contributes to the relatively unreliable performance of currently available military tracer ammunition. Military specifications usually set forth the common "trace" requirement that ninety to ninety-five percent of the tracer projectiles actually trace at a reliability level of ninety percent. Ammunition manufacturers have experienced difficulties in meeting such standards. The presently employed consolidation process and the use of standard metal-oxidizer chemical formulation has led to various ammunition malfunctions such as "blinds" (wherein there is no tracing at all), short traces, dim traces or even the ejection of all or part of the pyrotechnic composition during flight (usually called "popout"). Further difficulties have been experienced by prior workers in the art because the proper functioning of many tracer compositions exhibited an undesirable dependence on the ambient temperatures.
Additionally, inasmuch as present small-arms tracer projectiles often do not or can not have the same exterior ballistics as the companion (non-tracer) projectiles such as ball projectiles or HE projectiles, which they must simulate in flight trajectory, it will be appreciated that other design and manufacturing problems exist which have not been fully mastered by those skilled in the art of tracer ammunition production.
It has been found by prior workers in the field that the reliability of ignition and the burning time of a tracer is a sensitive function of several manufacturing and environmental variables. The tracer assembly takes up critical space in the round as a whole and is not readily compatible with other ammunition types. Further, the tracer functioning can perturb the exterior ballistics, and because of this, tracer sub-caliber rounds for large caliber systems or the same caliber tracer rounds for small caliber systems can experience ballistic mismatches as compared with the main or non-tracer round when in flight.
Additionally, the presently available tracer ammunition usually exhibits poor visibility at long ranges from the gunner's location. The relatively large pyrotechnic display of the presently available tracer ammunition provides a close range of visibility which may serve as a locater and thus permit enemy detection of the firing source. Accordingly, many gunners have been faced with the choice of disgarding tracer ammunition entirely and thus losing the accuracy and locating affect of the tracer rounds or else, by employing the tracer ammunition for accuracy purposes, they might then find themselves unduely attracting return fire because of the locater effect of the tracers. Further, it has been found that in many instances, certain chlorinated ingredients of current tracer compositions have histories of manifesting carcinogenic effects during manufacturing, thereby possibly creating a considerable job hazard Additionally, as above set forth, automated tracer manufacturing procedures have not heretofore been available and accordingly, the cost of tracer ammunition manufacturing is considerably greater than that of the main, non-tracer rounds.
It is therefore an object of the present invention to provide an improved tracer ammunition of the type set forth.
It is another object of the present invention to provide a novel tracer ammunition featuring pyrotechnic columns including means to produce long burning times with highly intense displays visible over long ranges.
It is another object of the present invention to provide a novel small arms tracer ammunition which can be manufactured utilizing the same equipment and the same manufacturing techniques which are employed when manufacturing the non-tracing rounds.
It is another object of the present invention to provide a novel tracer ammunition featuring a pyrotechnic column characterized by a length-to-diameter ratio which exceeds the value of five.
It is another object of the present invention to provide a novel tracer ammunition including a pyrotechnic column of small diameter and means to slow the burning rate of the pyrotechnic column.
It is another object of the present invention to provide a novel method of manufacturing an improved tracer ammunition wherein the need for a drilled hole ro receive a pyrotechnic composition in the base of the projectile can be eliminated.
It is a further object of the present invention to provide a metal encased tracer element for use in cannon caliber ammunition.
It is another object of the present invention to provide a novel tracer ammunition and an improved method of manufacturing the same.
Other objects and a fuller understanding of the invention will be had by referring to the following description and claims of a preferred embodiment thereof, taken in conjunction with the accompanying drawings, wherein like reference characters refer to similar parts throughout the several views and in which: